To form a structure having high-aspect holes or grooves by using a pattern formed based on a lithography technology, a mask material having high etching resistance is required. Further, to transfer a resist pattern to a material having high etching resistance such as a metal, a technology for performing dry etching with respect to this material is important.
In the prior art, a physical etching effect or a corrosive gas is used for patterning a metal material having high dry etching resistance.
However, perpendicular processability is low in the physical etching, and forming a mask that enables formation of a high-aspect hole or groove structure is difficult. Further, for example, when a halogen gas is used, there occurs a problem that a metal material corrodes and processing residues remain to contaminate a processing target under the mask.